Integral pneumatic tire and wheel construction and method of making the same



J. H. McHU GH 3,466,211 INTEGRAL PNEUMATIC TIRE AND WHEEL CONSTRUCTIONAND Sept. 9, 1969 METHOD OF MAKING THE SAME Original Filed Nov. 26, 19653 Sheets-Sheet 1 INVENTOR.

JAMES H. M'HUGH ATTORNEY Sept. 9, 1969 J. H. McHUGH 3,

. INTEGRAL PNEUMATIC TIRE AND WHEEL CONSTRUCTION AND METHOD OF MAKINGTHE SAME Original Filed Nov. 26. 1965 3 Sheets-Sheet 2 INVENTOR. JAMESH. M'HUGH ATTORNEY BYWZM Sept. 9, 1969 J. H. MCHUGH 3,466,211

INTEGRAL PNE AT TIRE AND WHE CONSTRUCTION AND MET D MAKING THE S EOriginal Filed Nov. 26, 1965 3 Sheets-Sheet 5 L g I44 L INVENTO R. JAMESH. MHUGH ATTORNEY United States Patent 3,466,211 INTEGRAL PNEUMATIC TIREAND WHEEL CON- STRUCTION AND METHOD OF MAKING THE SAME James H. McHugh,408 S. Belmont, Wichita, Kans. 67218 Original application Nov. 26, 1965,Ser. No. 509,730, now Patent No. 3,362,451, dated Jan. 9. 1968. Dividedand this application Aug. 30, 1967, Ser. No. 683,745

Int. Cl. B29h 17/10 U.S. Cl. 156-123 4 Claims ABSTRACT OF THE DISCLOSUREThis invention pertains to a method for making a unitary pneumatic tire,rim and wheel of molded construction wherein the rim has embeddedtherein extensions of fabric disposed in the tire body and fabricdisposed in the wheel. The method involves molding the tire body withfabric embedded therein projecting from both of the opposite rim edgesof the tire body, then molding one half of the rim and wheel and fabricembedded therein to one rim edge of the tire body and to the fabricprojecting from such rim edge of the tire body, and finally, with aninflated bladder in the tire body, molding the other half of the rim andwheel to the other rim edge of the tire body and the fabric projectingtherefrom.

This is a division of application Ser. No. 509,730, filed Nov. 26, 1965,now U.S. Patent 3,362,451.

This invention relates to new and useful improvements in pneumatic tiresand methods of making the same, and more particularly relates to anintegral pneumatic tire, rim and wheel construction and methods ofmaking the same.

Generally speaking, the present invention involves new and usefulimprovements in structure and methods with respect to the prior art asexemplified by U.S. Patent No. 3,062,254 which issued to Keefe, Nov. 6,1962, on Molded Wheel Having Internal Reinforcing; U.S. Patent No.3,117,614 which issued to Amici, Jan. 14, 1964, on Combined PneumaticTire and Rim Assembly; and, U.S. Patent No. 3,047,041 which issued toBottasso et aL, July 31, 1962, on Pneumatic Tire With Integral Rim.

The primary object of the present invention is to provide a unitarypneumatic tire, rim and wheel construction fabricated entirely bymolding techniques, and wherein such portions of the structureconstituting elements termed rim portions or rim flanges of conventionalconstruction have embedded therein extensions of tire body or tirecarcass fabric ply materials as well as extensions of bonded or embeddedfabric in the wheel to achieve optimized strength in the connection ofthe tire body to the rim and the latter to the wheel.

Another important object of the invention is to provide a constructionsuch as specified above which will require a minimum of materials in thesidewall portions of the tire body or carcass so as to minimize thegenera tion of heat during sidewall flexure occasioned during tireusage.

Another important object is to reduce the overall cost of a pneumatictire, rim and wheel to such a low level that it is economical to replacesuch an entire assembly upon the tire portion thereof wearing out, andto thereby enable enjoyment of the economy of avoidance of such tasks asthe mounting of a new tire upon a rim, etc.

Still another object of the invention is to provide an integralpneumatic tire, rim and wheel construction such that the same can bemarketed as an assembly that is pre-balanced from both the static anddynamic standpoints.

One aspect of the invention involves an integral pneumatic tire andwheel construction comprising an annular wheel having an integralperipheral rim, said wheel and rim being comprised of a fabric of hightensile strength fibers bonded by a plastic or resin material and ofsufficient resilient strength and rigidity to support substantial radialand axial static and shock loads presented thereto, said rim includingopposite and laterally extending portions generally conformable inconfiguration to a torus embracing the wheel and termination in marginaledges, an annular tire body constituted of fabric ply layers embedded inand bonded to elastomeric sealing material, said tire body beingC-shaped in section and having marginal edge portions, said marginaledge portions of the tire body abutting the marginal edges of the rimwhereby the tire body and the rim generally conform to the torus andenclose a torus-shaped space in an airtight fashion, said fabric ply ofthe tire body being extended from each of the abutting marginal edgeportions of the latter and being securely embedded in the resin bondingmaterial of the oppositely extending portions of the rim, and anelastomeric tire tread material bonded on the radially outermost side ofthe tire body.

Another aspect of the invention involves in the method of making anintegral pneumatic tire and wheel, the steps comprising radiallysuperposing and sealing together with an impregnating elastomer andcentral portions of a series of fabric ply layers to form an integralannular multi-ply tire body having the lateral side margins of thefabric ply material freely extending therefrom, positioning the lateralside margins of the fabric material at one side of the tire body in amold cavity definitive of an annular semi-rim and wheel shape,positioning annular layers of fabric material in the mold cavity tooverlap said side margins of the fabric ply material at said one side ofthe tire body, filling the mold cavity with a curable resin and curingsaid resin to form a. semi-resin and wheel integral with the tire bodyat said one side of the latter, positioning the thus formed tire bodyhaving the side margins of the fabric material extending from the otherside thereof and the integral semi-rim and wheel at said one sidethereof in an annular mold cavity and about an inflatable torus-shapedbladder, positioning annular layers of fabric material in the lastmentioned mold cavity to overlap the last mentioned side margins offabric material, placing a curable resin in the last recited mold cavityexternally of the bladder and about the fabric material at said otherside of the tire body, inflating the bladder by insertion of a fluidunder pressure thereinto, and curing the resin while the bladder isinflated.

An important feature of the invention resides in fabric ply material ofthe tire body or carcass being embedded in a: cured resin constitutingeffectively a rim so as to achieve a secure and integral connectionbetween the tire body or carcass and the rim and at the same time toeffect reinforcement of the synthetic resin constituting the rim, and sothat any provision of structure analogous to the conventional head ofpneumatic tires is avoided.

Another important feature of the invention is the provision of anintegral rim and wheel with each of such portions of the structure beingconstituted of a cured synthetic resin which may include fiberreinforcement such as comprised of fibers of glass, nylon, and the like.While not being absolutely essential, it is much preferred as a featureof this invention that the fiber reinforcement be woven as a fabric,with it being especially preferred that such reinforcement be in thenature of laminations of glass fiber fabric or textile impregnated andbonded together in a compact mass with a synthetic resin such as anepoxy resin.

Still another feature of the invention resides in overlapping annularlayers of fabric ply material with the fabric ply layers that extendabout the center of the tire to strengthen the tire with respect toradial stresses as well as with respect to loads applied to the tire ina tangential direction such as occur during acceleration anddeceleration of a vehicle provided with such tire.

Other important features of the invention relate to steps performedduring manufacture of the integral pneumatic tire, rim and wheelconstruction of this invention with particular importance being attachedto the two-step molding of the opposite sides of the rim and wheel, withthe second step being performed with the tire being inflated by theinjection of a fluid under pressure into an inflatable bladder disposedtherein.

These and other objects, aspects and features of the invention willbecome evident and fully appreciated in the light of the followingdescription of a preferred embodiment of the invention and methods ofmaking the same when taken in conjunction with the accompanyingdrawings, wherein:

FIGURE 1 is a vertical sectional view taken in the plane of the axis ofthe structure with the pneumatic tire portion thereof being illustratedin dashed outline;

FIGURE 2 is an enlarged fragmentary sectional view taken in the plane ofthe axis of the construction and along a radius thereof and illustratingparticularly the pneumatic tire portion, the rim portion and adjacentportions of the wheel;

FIGURE 3 is a fragmentary side elevational view of the structure of thisinvention on an enlarged scale and with portions thereof being brokenaway to illustrate in section and relationship of various layers ofmaterial incorporated in the same; I

FIGURE 4 is a vertical sectional view of a preliminar state in thefabrication of the structure, the View being taken upon the plane of theaxis of the construction;

FIGURE 5 is an enlarged fragmentary illustration of the layers of bondedfabric ply material disposed about the mold or form shown in section inFIGURE 4;

FIGURE 6 is a transverse sectional view taken upon the plane of thesection line 66 in FIGURE 5;

FIGURE 7 is a transverse vertical view taken upon the plane of the axisof the structure resulting from removal of the superposed and bondedfabric ply materials shown in FIGURE 4 from the mold or form;

FIGURE 8 is a central sectional view taken upon the plane of the axis ofthe structure and illustrating in particular the molds employed todefine a mold cavity and wherein a synthetic resin is formed and curedto constitute a portion of the rim and wheel construction with fabricply material of the tire body extending into and embedded within suchsynthetic resin; and

FIGURE 9 is a sectional view taken upon the plane of the axis andshowing an ensuing step of fabrication wherein the other portion of therim and wheel construction is molded and cured from a synthetic resinwith fabric ply material embedded therein.

Referring now to the drawings wherein like numerals designate like partsthroughout the various views, the reference numeral 10 designates theintegral pneumatic tire, rim and wheel construction generally. Theintegral construction 10 will be seen upon reference to FIG- URES 1through 3 to comprise a pair of annular plates or wheel portions 12 and14 which are of corresponding radial extents and are comprised of acured thermo setting resin material characterized by being hard andresilient in the interests of toughness, strength and resistance to heatsuch as for example suitable forms of epoxy and phenolic resins, andpreferably the resin material of the wheel portions 12 and 14 includeembedded therein fibrous reinforcing material which can conveniently befor example glass, nylon, or metallic fibers such as of steel ornonferrous metal. It is highly preferred that the resin material bereinforced with a fabric woven of such fibers (glass fibers beingpreferred in this role). Insofar as is now known best results can beobtained by the wheel portions 12 and 14 each being constituted of alaminated structure formed by layers of fabric of woven glass fibersimpregnated by and bonded together by the resin as a compact mass. Suchlaminated structure of the plates 12 and 14 is illustrated in FIGURE 2wherein the numerals 16, 18, 20, 22 and 24 designate resin bonded layersor laminations of fabric woven of fibers of glass constituting the plate12. Correspondingly, the plate 14 includes similar bonded laminations26, 28, 30, 32 and 34. More or less laminations can be employed as willbe evident. This aspect of the invention will be readily understood bythose skilled in the art as it is conventional to include asreinforcement such materials in synthetic resins such as commonlyreferred to as epoxy resins.

The wheel portions 12 and 14 jointly define a central opening 36, and inthe preferred construction means is provided for reinforcing the wallsor wheel portions 12 and 14 about the opening 36 such that canadditionally serve the purpose for mounting the assembly 10 upon theaxle or spindle of the automobile or the like in the conventionalmanner. Such means preferably comprise a pair of annular metallic plates38 and 40 disposed upon opposite sides of the wheel portions 12 and 14about the opening 36, and conventional fastening means such as thoseindicated at 42 are circumferentially spaced about the opening 16 andextended through the annular metallic rings or attachment plates 38 and40 through the wheel portions 12 and 14 disposed therein to retain suchelements in assembled relationship. Though not shown, additionalopenings can be circumferentially spaced through the structure about thecircumferential extents of the annular rings or mounting plates 18 and20 whereby the assembly 10 can be mounted upon the threaded studsconventionally provided in the wheel mounting structure of automobiles.

In the preferred construction, the adjacent faces of the wheel portions12 and 14 are securely bonded to each other throughout their radial andcircumferential extents along the plane of their juncture indicated at44; however, such is not absolutely necessary inasmuch ascircumferentially spaced fastening means, not shown, can be appliedthrough such members adjacent their radially outermost peripheries tohold such members against separation, as will be readily appreciated.Whatever means that may be provided for securing the wheel portions 12and 14 together, it will be evident that such means serve to preventradial movement of air between the plates or wheel portions 12 and 14.

Integral with the wheel portions 12 and 14 are oppositely extending rimflanges or semi-rims 46 and 48, such rim flanges 46 and 48 constitutingcontinuations of the portions 12 and 14 with which they are integrallyformed, it being noted that the laminations 16-34 extend thereinto. Thesemi-rims or rim flanges 46 and 48 are as shown of substantial wallthickness so as to be sufficient in themselves insofar as strength andresilient rigidity are concerned to be the full equivalent for theirfunctional purposes to the conventional steel wheel rims conventionallyemployed for automotive wheels for the mounting of pneumatic tires.

Directing attention principally to FIGURE 2 of the drawings, it will beseen that the rim flanges 46- and 48 jointly define a contour generallyconformable to a torous disposed about the circumferential periphery ofthe wheel portions 12 and 14. In other words, the radially outwardsurfaces of the rim flanges 46 and 48 generally define a surface ofrevolution that is concave along the axial extent of the wheel 10.

A tire body or carcass is designated generally at 50 having a central orradially outermost portion 52 and sidewall portions 54 and 56 contiguousthereto that merge with and are secured to the remote or outer marginaledges 58 and 60 of the rim flanges 46 and 48, respectively. The tirebody or carcass 50 throughout the transverse extent of the tire isconstituted of superposed layers of fabric ply material such as thelayers indicated at 62 and 64, such layers of fabric ply material being,as is conventional, impregnated with a sealing and bonding elastomericmaterial such as indicated at 66 which serves additionally to bond thelayers 62 and 64 together.

The fabric ply material layers 62 and 64 can be constituted of anymaterial such as is conventionally used for such purposes in pneumatictires, such as cotton, rayon and nylon. Such fabric ply material can andis preferably in the practice of the present invention comprised ofwoven glass fibers in the interest of achieving a high degree ofresilience, strength and resistance to any deleterious effects that maybe caused by high temperatures or stresses. Notwithstanding suchindicated preference, it will be understood that substantial benefit canbe realized in the practice of the present invention when using anyother form of natural or synthetic fibers in a woven form to constitutea fabric or textile for the formation of the superposed and bondedlayers or plies 62 and 64. It will be evident that a greater or lessernumber of such ply layers can be employed than shown if desired, and itis only essential in the practice of this invention that at least one ofsuch layers be employed.

The layers of fabric ply material 62 and 64 are extended around theextents of the sidewalls 64 and 66 and extend into and are embeddedwithin cured resin material of the semi-rims or rim flanges 24 and 26 tooverlap one or more of the laminations 16-44 therein. It will thus beseen that the tire carcass or tire body 50 jointly with the rim flanges46 and 48 jointly define a torus-shaped space 70 within which air isconfined under pressure when the pneumatic tire portion of theconstruction is inflated. The introduction of air is accomplishedthrough a conventional valve, not shown, in the rim flange 46. Theinternal surfaces of the torus-shaped surface defined by the tirecarcass or body 50 and the rim flanges 46 and 48 are lined with a layer72 of an elastomeric material generally in the nature of conventionalinner tubes and which may be made of the same character of materialsemployed therefor such as. natural soft rubber or synthetic materials ofsimilar characteristics such as butyl rubber.

An elastomeric tire tread material 74 of conventional character isbonded or vulcanized about the external surface of the tire carcass ortire body 50, such material 74 being applied as a relatively thin layeras indicated at 76 and 78 about the sidewall portions 54 and 56 asshown, and with such tread material 74 being extended about and bondedto the outer peripheral margins of the rim flanges 46 and 48 asindicated at 80 and 82. The tread material 74 is applied, as isconventional, in substantially increased thickness to the centralportion 52 of the tire body 50 as indicated at 86, preferably with treadgrooves 88 formed therein.

An annular sheet of fabric ply material 90 generally similar incharacter to the material employed for the layers 62 and 64 or for thelaminations 16-34 is superposed over overlapping extents of thelaminations 16-24 and 62 and 64, with such sheet 90 extending from wellwithin the rim flange 46 to well into the sidewall 54. More than onesheet 90 can be employed if desired, it being understood that the sheetor sheets 90 are securely bonded by the resin to the ply layers 66 and64 and also to the laminations 16-24. A sheet or sheets 92 correspondingto the sheet or sheets 90 are incorporated in a like manner in the rimflange 48 and the sidewall 56.

It is preferred that the reinforcing layers of fabric ply material 90and 92 extend from within and from the outermost extremities of the rimflanges 46 and 48 well up into the sidewalls 54 and 56 toward thecentral portion 32 of the tire body 30. The annular shaped sheets offabric ply material and 92 greatly reinforce the strength of thestructure and particularly reinforce the integral construction of thetire body 50 and the rim structures 46 and 48, and at the same timesubstantially strengthen the tire construction 10 against stressesimposed tangentially as when the tire is employed to rapidly accelerateor decelerate a vehicle on which it may be mounted. Inasmuch as thepreferred method of fabricating the structure 10 involves the layers 62and 64 being circumferentially discontinuous in the region at which theyapproach the rim flanges 46 and 48, the layers 90 and 92 overcome theweakness that would otherwise result. Though only one of each of thelayers 90 and 92 is shown in conjunction with each of the rim flanges 46and 48, it will be understood that a plurality of superimposed layers ofsuch material can be employed.

Attention is now directed to FIGURES 4 through 9 for an appreciation ofthe preferred and novel method for making the structure 10.

Directing initial attention to FIGURES 4 through 6, the referencenumeral 94 designates schematically a mold or form (which may be aconventional, radially collapsible type) having preferably though notnecessarily a convex circumferential external surface 96 upon which aresuperimposed a plurality of layers 98 of fabric ply material such as toultimately constitute the layers of such material designated at 62 and64 in FIGURE 2. Such layers of fabric ply material 98 extend as clearlyindicated at 100 and 102 in opposite directions from the surface 96 ofthe mold 94. The axial extents of the layers 98 coinciding with theaxial extent of the surface 96 are impregnated with, coated and bondedtogether by a sealing elastomeric material 103 such as neoprene, latexrubber, silicone rubber or butyl rubber. The layers 98 can of course besealed and bonded together by any other materials or methods of commonknowledge to those well versed in the art.

As clearly shown in FIGURE 5, the axial extents 100 and 102 of thelayers of ply fabric 98 applied about the mold 94 are notched asindicated at 104 and 106, with the notches of the various layers 98 ofsuch material being staggered with respect to each other as best shownin FIGURES 5 and 6. The notching is provided so that the individuallayers 98 of ply fabric can be formed from flat sheet material or fromcylindrically woven stock material and so that when the portions 100 and102 are bent about to conform with the configuration of the sidewalls ofthe finished product 10 such portions 100 and 102 along theircircumferential extents will not be gathered, bunched or excessivelyoverlapped or pleated. Alternatively, it will be appreciated that theindividual layers can if desired be specially woven or knitted so as toconform more readily to their finally desired configuration in theconstruction 10, in which event the desirability of the notching 104 and106 is not required. Each of the various layers 98 can be separate ordistinct, or can be a single continuous length of fabric woundcircumferentially about the mold 94 in the form of a spiral, with thesame being wound about the mold 94 by a number of turns equal to thenumber of ply desired. This latter method of building up the layers 98of ply fabric is applicable to the use of flat sheet fabric or textilematerial or to specially formed, woven or knitted fabric. Preferably thecentral portions of the fabric layers 98 are impregnated with theelastomer 103 prior to application to the mold 94. It will beappreciated as previously indicated that although the mold 94 isillustrated as a solid body, the same may be of the radially expansibleor collapsible type, whereby the bonded and sealed together fabriclayers 74 can be readily disengaged therefrom, and whereby asubstantially greater degree of convexity can be given the surface 72 ofthe mold. It is of course possible if desired to employ a common form ofcylindrical drum mold in lieu of the convex mold 94 illustrated, in

which event conventional processing techniques well known in the tiremanufacturing art can be applied to convert the layers 98 after removalfrom the mold to the configuration shown in FIGURE 7 as will be plain.

The elastomeric material 103 with which the ply layers 74 areimpregnated and sealed together can be such as to be curable upon theapplication of heat or include a setting agent so as to achieve adesired degree of strength wiihin a short period of time after thefabric and the materials constituting the fabric layers 98 have beenapplied to and formed on the mold 94. It will be understood from theforegoing that the axial extents of the ply fabric material coincidentwith the axial extent of the mold 94 can be impregnated with theelastomeric material prior to applying the same along with additionalbonding or sealing agent as may be necessary to the mold 94.- Forexample, such axial extent of the ply fabric can be impregnated withsettable silicone rubber prior to the application of the fabric to themold 94 with additional settable silicone rubber being applied betweensuch layers at the time the layers of impregnated fabric are applied tothe mold 94.

After the layers of ply fabric 98 have been suitably sealed and bondedtogether with the elastomeric material 103, impregnating and sealing thesame together has set, the resulting formed structure can be removedfrom the mold 70 (or the latter collapsed as indicated previously andremoved from within the structure), with the resulting product havingthe general appearance shown in central cross section taken upon theplane of the axis thereof shown in FIGURE 7. The extending fabricportions 100 and 102 can be preserved intact in their woven condition orfrayed (as can optionally be the case, it being noted that the notchingfacilitates such graying or unravelling) as suggested in FIGURES 7 and8. The step of fraying is entirely optional and can be omitted ifdesired.

A male mold member preferably made of steel is pro vided such as thatindicated at 110 in FIGURE 8. The upper surface of the male mold memberincludes a flat central portion 112 surrounding an upstanding centralboss 114 that respectively defines in the final product the outersurface of the wheel plate 14 and the wheel opening 36. Additionally,the height of the boss 114 fixes the axial spacing of the male mold 110from a female mold 116. The upper surface of the male mold also includesa generally frusto-conical portion 118 that at its outer peripheryterminates in a curved portion 120. The portions 118 and 120 serve todefine in the final product the outer surfaces of the rim flange 48 anda connecting extent of the sidewall of the tire.

Initially the upper surfaces 112, 118 and 120 are coated with a suitableparting compound such as silicone grease and over such parting compoundis applied a coating of a curable resin 122, after which one or moreannular sheets or layers of fabric ply material 124 are alternatelyapplied with additional resin 122 over the surfaces 112, 118 and 120.

The sheet or sheets of fabric 124 are preferably woven of fibers ofglass, though conventional fabrics suitable for the forming of tire plycan be used. The annular sheet or sheets 124 can be loomed if desired asa tight weave to conform to the configuration of the surfaces 112, 118and 120, or alternatively, the annular sheet or sheets 124 can be offlat annular configuration of sufliciently soft or loose weave as to bepressable upon the surfaces 112, 118 and 120 to conform thereto inconfiguration without wrinkling or pleating.

The extended portions 102 of the fabric layers 98 are also dressed,whether frayed or notched woven fibers, with additional resin 122 tofill and constitute a solid mass therewith, over the surface 120 andpreferably at least a portion of the surface 118 so as to radiallyoverlap and be bonded as a compact mass to the layer or layers 124. Thematerial portions 102 can be extended to cover a portion of the moldsurface 112 if desired.

It will be understood that the dressing of portions 102 will be asuniformly distributed circumferentially as possible so as to have thecentral axis of the mold as an axis of symmetry. Also the parts of theportions 102 radially inward of the layer 124 are preferentially dressedto extend toward the axis of the mold 110.

When a plurality of layers 124 are employed, it is preferred that suchlayers 124 be interdigitated with successively applied parts of theportions 102, it being noted that normally the portions 102 are inthemselves extensions of a plurality of ply layers 98.

When only one layer 124 is employed, it is preferred that it beinterposed between the mold 110 and all the portions 102; however, suchis not essential and such one layer 124 can overlie all or be disposedbetween parts of such portions 102.

The hereinbefore described application of the ply portions 102, thelayer or layers 124 and the resin 122 can be readily applied from above(as viewed in FIGURE 8) through the ample space between the free ends ofportions 100 of the ply material layers 98.

After such application with the resin being extended radially outward tothe edge of the elastomer 103 bonded layers 98 (such edge overlying themold surface 120 as shown), the female mold 116 having an undersurface132 generally similar to the surfaces 112, 118 and 120 is positioned asshown in FIGURE 8 and pressed downward upon the boss 114 of the mold110. The height of the boss 114 fixes the spacing of the surface 143(previously coated with a parting agent) from the surfaces 112, 118 and120. The amount or volume of resin 122 previously applied is controlledso that the same together with the tire body marginal portion at theedge 130, the portions 102 and the layers 124 at least completely fillthe space between the surface 132 and the surfaces 112, 118 and 120. Anyexcess resin 122 can be wiped from about the peripheries of the moldmembers 110 and 116 prior to the resin 122 setting or hardening. Theperipheral margin of the elastomer 103 bonded ply layers 98 along theedge 130 constitutes, as will be appreciated, such a seal that asubstantial pressure can be exerted on materials confined within thespace between mold members 110 and 116, whereby a good contact andexclusion of voids is facilitated.

After the resin 122 has cured, or hardened, the mold members 110 and 116are removed and an opening 136 is made therethrough and the previouslyformed half of the tire structure is seated in mold member 140 having anannular groove or trough 142 therein, after the mold member has beencoated with a parting compound to prevent adherence to the product.

An annular tube 144 generally similar to conventional inner tubes andwhich can be made of such conventional materials such as butyl rubber,latex rubber, etc., is disposed in deflated or near deflated conditionwithin the previously formed half of the tire and a valve fitting 146with which the tube 144 is provided is extended to project through theopening 136 so as to communicate with an opening 148 in the mold member140. Preferably a curable sealing agent such as commercially availableforms of silicone rubber, or the like is applied about the air tube orvalve fitting 146 to form a bonded seal with the portion of the tirethrough which the opening 136 extends. The arrangement is such that airand desired fluid can be forced through the opening 148 to inflate thetube 144.

If desired the external surface of the tube can be coated with anysuitable form of curable cement or bonding agent so that the tube 140will constitute an integral portion of the completed product.

After the tube 144 has been arranged as described above with respect tothe mold member 140, the tube 144 is partially inflated to be nearly butpreferably slightly smaller in size than it will be in the finalproduct. The flat side 150 of the structure formed thus far is coated ornot coated with a parting agent depending, as will be under- 9 stood, onwhether it is desired that the wheel plates 12 and 14 in the finalproduct are to be bonded together or to be separable.

The portions 100 of the elastomer 103 bonded ply layers 98 are alongwith resin 152 dressed over the side of the tube 144 remote from themold member 140 to extend a comparable distance toward the axis of themold member 140 as do the previously described portions 102 now embeddedin and bonded by resin 122. In addition, layers of annular fabric 154along with resin 152 are applied over the surface 150 and over the tube144 so as to overlap the fabric portions 100. The application of thefabric portions 100 and the layers of fabric material 154 are with theresin 152 (preferably, though not necessarily) applied in such a mannerand sequence so as in the final product to have the surface 150 as aplane of symmetry. Obviously, the fabricator in the practice of themethod is as free in the exercise of his preference for the sequencingor ordering of the various layers of fabric as indicated previously withrespect to forming the other side of the combined wheel and tire.

Thereafter, the previously described male mold memher 110 is positionedas shown in FIGURE 9 (the same having its surfaces coated with asuitable parting compound) and the mold members 140 and 110 are pressedtogether until the boss 114 engages the mold member 140 as shown. Then,air or any suitable fluid is applied under pressure through the opening148 in the mold member 140 to inflate the tube 144 under asuperatmospheric pressure, preferably a pressure in excess of 100 poundsper square inch, though lower pressures may be employed if desired.During such pressure inflation of the tube 144, any suitable means, notshown, are employed to prevent separation of the mold members 110 and140. The quantity of resin 152 applied is preferably of suchpredetermined quantity so as to fill the space between the mold members110 and 140 to the extent shown in FIGURE 9. As will be evident, caremust be exercised during placement of the mold member 110 so as toprevent the inclusion of air pockets. If desired, a slight excess ofresin 152 can be applied and the mold members 110 and 140 bereciprocated a short distance towards and away from each other prior toseating the boss 114 against the mold member 140 with alternateapplication and relief of air or fluid pressure within the tube 114 soas to tend to cause excess resin as well as any pockets of included airto migrate radially outward to the outside of the mold members 110 and140. Also, the mold members 140 can have its outer peripheralundersurface 160 slightly spaced from the mold member 110 when the boss114 engages the center of the mold member 140 so that air can be free atall times to migrate radially outward from between the mold members. Ofcourse, the gap between the mold members 110 and 140 about theirperipheries must be sufliciently small so as to prevent any damagingextrusion of the already formed portion of the tire therebetween byreason of the fluid pressure existing within the tube 144.

After the resin 152 has cured or set, which curing or setting can ifdesired be accelerated by placing the structure shown in FIGURE 9 withina suitable oven, the mold members 110 and 140 are removed from theproduct as thus far formed.

Finally the molded structure shown in FIGURE 9 has the tread rubber 74molded and vulcanized thereon by conventional procedures to result inthe final product disclosed in FIGURES 1, 2 and 3.

The illustrated and described product as well as the illustrated anddescribed preferred method for making the product are subject tonumerous variations in detail without departing from the spirit of theinvention, and accordingly, attention is directed to the appended claimsin order to ascertain the actual scope of the invention.

I claim:

1. In the method of making an integral pneumatic tire and wheel, thesteps comprising radially superposing and sealing together with animpregnating elastomer the central portions of a series of fabric plylayers to form an integral annular multi-ply tire body having thelateral side margins of the fabric ply material freely extendingtherefrom, positioning the lateral side margins of the fabric materialat one side of the tire body in a mold cavity definitive of an annularsemi-rim and wheel shape, filling the mold cavity with a curable resinand superposed and overlapping layers of fabric and the side margins ofthe fabric material at one side of the tire body, curing said resin withthe side margins of the fabric material at one side of the tire body andthe overlapping layers of fabric embedded therein to form a semi-rim andwheel portion integral with the tire body at said one side of thelatter, positioning an inflatable annular member within the thus formedsemi-rim and wheel portion integral with the tire body, applying theside margins of the fabric material at the other side of the tire bodytogether with overlapping and superposed layers of fabric to the annularmember together with a curable resin, said superposed layers of fabricbeing arranged to extend radially inwardly from the annular member,molding the last mentioned side margins of the fabric material,superposed layers of fabric and resin to form a second semi-rim andsecond wheel portion integral with the tire body, and curing the resin.

2. The method of claim 1, wherein a superatmospheric pressure ismaintained in the annular member during the last recited molding orcuring steps, and finally bonding tread material about the exterior ofthe tire body.

3. The method of claim 1, wherein the curable resin applied to theannular member is also applied directly to and subsequently bonded oncuring to the first mentioned wheel portion, whereby the two wheelportions are effectively bonded directly together as an integral unit.

4. The method of claim 1, wherein a parting compound is applied to thefirst mentioned wheel portion to prevent the two wheel portions frombeing bonded together on executing the last recited curing step.

References Cited UNITED STATES PATENTS 1,192,994 8/1916 Dees 156-123 X1,289,772 12/1918 Hopkinson 264-315 X 2,071,864 2/1937 Myers 156-1102,251,661 8/1941 Colley 264-326 X 2,605,200 7/1952 Iknayan 156-123 X2,612,461 9/1952 Hallgren 264-326 3,142,597 7/1964 Anderson et al. 2----156-123 3,218,209 11/1965 Travers et a1 156-123 EARL M. BERGERT, PrimaryExaminer C. B. COSBY, Assistant Examiner US. Cl. X.R.

